USE OF AMPHOTERICIN B AS OPTICAL PROBE TO STUDY CONFORMATIONAL CHANGES AND THERMODYNAMIC STABILITY IN HUMAN SERUM ALBUMIN

ROMANINI DIANA; MÜLLER GABRIELA; PICÓ GUILLERMO

JOURNAL OF PROTEIN CHEMISTRY

Springer Netherlands

Lugar: Netherlands; Año: 2002 vol. 21 p. 505 - 514

0277-8033

The binding of polyene antibioticamphotericin B to serum albumin was studied using absorption, fluorescencehypochromic effect was observed in the absorption spectrum of amphotericin B in the presence of albumin with maxima at366 nm, 385 nm and 408 nm, which corresponds to the absorption of the monomeric form of amphotericin B. A modif ication onthe circular dichroism spectrum of amphotericin B in the presence of albumin was observed at 329 nm and 351 nm suggests that only amphotericin B monomer is bound to the protein. Amphotericin B perturbs the specific markers for sites I, II and fatty acid binding site bound to these sites, suggesting that Amphotericin B interacts with a great binding area in albumin. Lysines 199 and 525 in albumin participate in the molecular interaction between amphotericin B and the protein. The absorption spectrum of Amphotericin B bound to albumin was sensitive to the chemical and thermal treatment of the protein,neutral-basic transition of albumin and conformational changes induced by the binding of other ligands to this protein